Volcanoes

সারসংক্ষেপ

A volcano is an opening through which magma, ash and volcanic gases reach Earth's surface.

মূল ধারণা

ব্যবস্থাটি বুঝুন

A volcano is an opening through which magma, ash and volcanic gases reach Earth's surface.

কেন ও কীভাবে ঘটে

কারণ ও প্রেক্ষাপট

A volcano is an opening through which magma, ash and volcanic gases reach Earth's surface. The governing relationship is: Decompression melting, addition of water at subduction zones or mantle plumes produces magma that rises because it is buoyant and less dense.

কীভাবে কাজ করে

Decompression melting, addition of water at subduction zones or mantle plumes produces magma that rises because it is buoyant and less dense.

মূল তথ্য

• Magma is underground; lava is magma erupted at the surface.
• Shield volcanoes are broad and commonly basaltic; stratovolcanoes are steeper and often more explosive.
• Volcanic ash consists of fine fragmented material, not soft burning ash.

গুরুত্বপূর্ণ পরিভাষা

• magma
• lava
• pyroclast
• caldera
• stratovolcano

উদাহরণ ও কেস স্টাডি

• Mount Fuji is a stratovolcano associated with subduction in Japan.

কারণ ও উপাদান

• Key components: magma, lava, pyroclast.
• Decompression melting, addition of water at subduction zones or mantle plumes produces magma that rises because it is buoyant and less dense.

প্রভাব ও গুরুত্ব

• Shield volcanoes are broad and commonly basaltic; stratovolcanoes are steeper and often more explosive.
• Volcanic ash consists of fine fragmented material, not soft burning ash.
• Application: Mount Fuji is a stratovolcano associated with subduction in Japan.

ভূগোলের সাথে সংযোগ

Mount Fuji is a stratovolcano associated with subduction in Japan. This illustrates how volcanoes varies by location, scale or environmental context.

বাংলাদেশের সাথে সংযোগ

Bangladesh has no active volcanoes; its volcanic-ash and tectonic discussions are regional, linked to the wider Indo-Burma arc.

BCS প্রিলিমিনারির তথ্য

• Magma is underground; lava is magma erupted at the surface.
• Shield volcanoes are broad and commonly basaltic; stratovolcanoes are steeper and often more explosive.
• Volcanic ash consists of fine fragmented material, not soft burning ash.

BCS লিখিত বিশ্লেষণ

একটি বিশ্লেষণধর্মী উত্তর তৈরি করুন

• A volcano is an opening through which magma, ash and volcanic gases reach Earth's surface.
• Decompression melting, addition of water at subduction zones or mantle plumes produces magma that rises because it is buoyant and less dense. Use mount fuji is a stratovolcano associated with subduction in japan. as a named application in a comparative answer.

প্রচলিত ভুল ধারণা

• A volcano is not simply a mountain; it is a vent and its associated edifice.
• All eruptions are not equally explosive; viscosity and gas content matter.

দ্রুত রিভিশন

• Volcanoes
• Magma is underground; lava is magma erupted at the surface.
• Shield volcanoes are broad and commonly basaltic; stratovolcanoes are steeper and often more explosive.
• magma / lava
• Definition → process → spatial example